The present invention pertains generally to micelles. In particular, the present invention relates to polymer-micelle complexes, as might be particularly useful in immobilizing contaminants.
Environmental contamination by organic compounds is one of the most ubiquitous and costly environmental concerns facing society today. Such contamination can be caused by leakage or spillage of various non-aqueous phase liquids, which generally are very limited in their ability to dissolve in water. The non-aqueous phase liquids can contaminate the environment from a variety of sources, such as, for example, spillage or leakage of large-volume solvents used and stored in chemical and other manufacturing production facilities. Strictly by way of example, acetone, benzene, toluene, xylene, and the like can be released to the environment from such facilities.
Contamination can also result from leakage of underground storage tanks, such as, for example, gasoline tanks at service stations. Although some newer storage tanks are equipped with a liner (e.g., a clay liner such as bentonite), such tanks nevertheless are susceptible to leakage, especially in cases where the fluids being held are caustic in nature (e.g., gasoline). Of course, leakage can be even more severe in older tanks in which minimal or no lining exists. Indeed, many tanks at service stations have been in existence since at least the 1950""s.
Upon release of such organic contaminants to the environment, a portion of the contaminants may volatilize harmlessly into the atmosphere in the gas phase. However, a significant portion of the contaminants may be released to the earth""s subsurface in the liquid phase. In this respect, the release of organic compounds into the earth""s subsurface can result in a plume of dissolved and pure phase organic compounds that can travel (e.g., down-gradient) with natural groundwater flow within a water-holding geologic unit known as an aquifer. Such contaminated subsurface water can travel hundreds of meters in a year, can be accidentally extracted in well-water, and can eventually surface in rivers and streams. Thus, even though this form of contamination is generally xe2x80x9cinvisible,xe2x80x9d it has significant deleterious environmental ramifications.
Prior approaches for containing such environmental contamination have not been fully satisfactory. For example, a common approach for handling the contamination is known as the xe2x80x9cpump and treatxe2x80x9d method. The xe2x80x9cpump and treatxe2x80x9d method entails pumping out pollutant-containing water from the earth""s subsurface. The contaminated water is treated to remove the contaminants and then returned to its original subsurface location. However, the xe2x80x9cpump and treatxe2x80x9d method suffers from a number of drawbacks. In particular, it has proven to be very difficult to track the location of additional pollutants after treated water is returned to the earth""s subsurface. In addition, the xe2x80x9cpump and treatxe2x80x9d method requires continual monitoring and pumping over a very long period of time (e.g., 20 or more years), and is therefore cumbersome and expensive.
Other strategies for addressing this problem have included air purging to remove volatile components, bioremediation, and soil removal. With respect to bioremediation, nutrients and oxygen are provided in the earth""s subsurface to allow natural microbial communities to break down organic material. Meanwhile, soil removal is utilized especially in instances where the contamination occurs near ground-level. The removed soil then is incinerated at a temperature sufficiently high to remove the contaminants by combustion. However, these other approaches also arc generally poorly effective, expensive (e.g., more than $1 million per acre for soil removal), and/or can require decades of active remediation.
Another major pollution problem relates to spent fluids from various industrial processes. For example, contaminated aqueous fluids are produced from offshore oil well recovery processes. Particularly, seawater is pumped out with oil, and often, various additives are included. Even after the oil is separated from the water, the water nevertheless includes various hydrocarbon contaminants (e.g., toluenes, benzenes, and the like). Heretofore, it has proven to be very difficult to properly treat (e.g., filter) the water before it is returned to the sea, thereby posing a significant environmental contamination problem.
Accordingly, it will be appreciated from the foregoing that there exists a need in the art for techniques for trapping organic compounds and, if desired. retaining them in trapped form for long periods of time. There is also a need for such techniques which also allow for extraction of the trapped organics at a later date, as desired. It is an object of the present invention to satisfy these needs. These and other objects and advantages of the present invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.
In one aspect, the present invention provides a polymer-micelle complex. The polymer-micelle complex comprises a negatively charged micelle which is electrostatically bound to a polymer bearing a positive charge.
In another aspect, the present invention provides a composition comprising an aqueous carrier, a micelle, and a polymer. In the composition, the micelle and polymer can remain separated, or, if desired, the polymer and micelle can electrostatically bind to form a complex, which can either be soluble or in the form of a precipitate or coacervate.
In addition, the present invention provides certain products and methods pertaining to the inventive complex and/or the inventive composition. For example, the present invention provides a filter, a method of treating fluids, a method of trapping organic contaminants, and a method of inhibiting seepage of organic contaminants.
Advantageously, the present invention provides a benign approach for removing organic contaminants without requiring continual processing and monitoring. In particular, the present invention permits organic compounds to be trapped and retained in trapped form for long periods of time. In addition, the present invention allows for extraction of the trapped organics at a later date, as desired.
The present invention will be more fully understood upon reading the following detailed description in conjunction with the accompanying drawings.